Figure 5.
Regulation of histone modifications after in vitro stimulation of hippocampal slices. A, Quantification of immunoblot densities for phospho-histone H3 (P-H3), acetyl-histone H3 (Ac-H3), dimethyl-histone H3 (Di-Me-H3), and acetyl-histone H4 (Ac-H4). Treatment of wild-type hippocampal slices (n = 7) with FSK (50 μm) plus Ro20–1724 (100 μm) for 1 h significantly increased H3 phosphorylation and acetylation, whereas preincubation with U0126 (20 μm) for 10 min followed by FSK blocked these changes. Treatment of MSK1 knock-out hippocampal slices (n = 7) with FSK plus Ro20–1724 for 1 h did not result in any significant changes in histone modifications, and preincubation with U0126 for 10 min followed by FSK had no significant effect. Total histone H3 was unchanged. Representative immunoblots for P-H3, Ac-H3, and total H3 are shown for FSK treatments. B, Quantification of immunoblot densities for phospho-histone H3, acetyl-histone H3, dimethyl-histone H3, and acetyl-histone H4. Treatment of wild-type hippocampal slices (n = 8) with PDA (3 μm) for 1 h significantly increased H3 phosphorylation and acetylation, whereas preincubation with U0126 (20 μm) for 10 min followed by PDA blocked these changes. Treatment of MSK1 knock-out hippocampal slices (n = 8) with PDA for 1 h did not result in any significant changes in histone modifications, and preincubation with U0126 for 10 min followed by PDA had no significant effect. Total histone H3 was unchanged. Representative immunoblots for P-H3, Ac-H3, and total H3 are shown for PDA treatments. Drug-treated and vehicle-treated slices for each condition came from one individual animal. All drug-treated slices were compared with vehicle-treated (DMSO) controls and normalized to total protein loaded. Error bars indicate SEM. Asterisks denote significant differences (p < 0.05) as determined by Tukey's multiple-comparison test.